are strong. ♪ pope benedict led a packed st. peter's basilica in a moving ash wednesday mass. reminding the faithful, they are made from dust and to dust they shall return. a message of humility, answered by an unusual demonstration of affection. a spontaneous, prolonged standing ovation for the retiring pontiff, at his final public mass. a sea of cell phones capturing the exit of a man praised today as a simple and humble worker. >> i have tears in my eyes. it's just so amazing to be here. >> reporter: the pope's weekly audience turned into a pep rally of sorts for the pontiff. an audience these tourists from dallas will not forget. >> i think it's a very big part of history. and we're very proud to be a little part of it. >> reporter: when benedict's papacy ends, the vatican says he will remove his ring, the symbol of his authority, and it will be destroyed. as happens when a pope dies. on his last day, february 28th, he will meet with the cardinal, many appointed by him, and they will choose his successor at a conclave that w